Especially one thats been dead for a decade and was no longer viable or welcome on the network that aired it, or any other Joss pitched it to for the next three years.

So it was dead for 3 years while it still lasted?

How was it "not viable or welcome on the network that aired it"? You've got some inside info from UPN 8 years ago? It sure was viable with 3.6 million viewers on average in its last season (not bad at all for a 7th season of a show whose highest average rating for a season was 5.3) and 4.9 for the finale, and I know of no reason why it wouldn't have been welcomed it if had continued. The show wasn't cancelled, it ended because SMG didn't want to go on playing Buffy and because they decided to end it. There was never any attempt to continue Buffy, on UPN or any other network. There was going to be a Faith spinoff that didn't happen because Eliza Dushku decided to be in Tru Calling.